Although the Upanishadic texts (like some of the earlier Vedic texts) are primarily concerned with acquiring knowledge of the “soul”, “spirit” and “god” – there are aspects of Vedic and Upanishadic literature that also point to an intuitive understanding of nature and natural processes. In addition, many of the ideas are presented in a philosophical and exploratory manner – rather than as strict definitions of inviolable truth.

Although the Upanishadic texts goaded the Upanishadic student to concentrate on comprehending the inner spirit, rational investigation of the world by other scholars was not entirely squelched, and eventually, the Upanishadic period gave way to an era which was not inimical to the development of rational ideas, even encouraging scientific observation and advanced study in the fields of logic, mathematics and the physical sciences.

Following an era when rituals and superstitions had begun to proliferate, in some ways the Upanishadic texts helped to clear the ground for greater rationalism in society. Brahmin orthodoxy and ideas of ritual purity were superseded by a spiritual perspective that eschewed sectarianism and could be practised universally, unfettered by an individual’s social standing. Much of the emphasis was on discovering “spiritual truths” for oneself as opposed to mechanically accepting the testimony of established religious leaders. Although there is a thematic commonality to the Upanishadic discourses, different commentators offered subtly varying perspectives and insights.

The concept of god in Upanishadic (and even earlier Vedic) thinking was quite different from the more common definition of god as creator and dispenser of reward and punishment. The Upanishadic concept of god was more abstract and philosophical. Different texts postulated the doctrine of a universal soul that embraced all physical beings. All life emanated from this universal soul and death simply caused individual manifestations of the soul to merge or mingle back with the universal soul. The concept of a universal soul was illustrated through analogies from natural phenomenon.

“As the bees make honey by collecting the juices of distant trees, and reduce the juice into one form. And as these juices have no discrimination, so that they might say, I am the juice of this tree or that, in the same manner, all these creatures, when they have become merged in the True, know not that they are merged in the True. . . .”

“These rivers run, the eastern (like the Ganges) towards the east, the western (like the Indus) towards the west. They go from sea to sea (i.e., the clouds lift up the water from the sea to the sky and send it back as rain to the sea). They become indeed sea. And as those rivers, when they are in the sea, do not know, I am this or that river, in the same manner, all these creatures, proceeding from the True, know not that they have proceeded from the True. . . .”

In another story, the “wise” father, expounder of the Upanishadic concept of god, asks his son to dissolve salt in water, and asked him to taste it from the surface, from the middle and from the bottom. In each case, the son finds the taste to be salty. To this his father replies that the ‘universal being’ though invisible resides in all of us, just as the salt, though invisible is completely dissolved in the water.

As a corollary to this theory emerged the notion that even as individual beings might refer to this universal soul – i.e. god in varied ways – by using different names and different methods of worship – all living beings were nevertheless related to each other and to the universal god, and capable of merging with the universal god. This approach thus laid the foundation for egalitarian and non-discriminatory philosophies such as Buddhism and Jainism (as well as non-sectarian streams of Hinduism) that followed the Upanishadic period. As is evident, such an approach was not incompatible with secular society, and permitted different faiths and sub-faiths to coexist in relative peace and harmony.

In the course of defining their philosophy, the scholars of the Upanishad period raised several questions that challenged mechanical theism. If god existed as the unique creator of the world, they wondered who created this unique creator. The logical pursuit of such a line of questioning could either lead to an infinite series of creators, or to the rejection or abandonment of this line of questioning. The common theist solution to this philosophical dilemma was to simply reject logic and demand unquestioning faith on the part of the believer. A few theists attempted to use this contradiction to their own advantage by positing that god existed precisely because “He” was indescribable by mere mortals. But, by and large, this contradiction was taken very seriously by the philosophers of the Upanishadic period. The Upanishadic philosophers attempted to resolve this contradiction by defining god as an entity that extended infinitely in all dimensions covering both space and time. This was a philosophical advance in that it attempted to come to terms with at least the most obvious challenges to the notion of god as a human-like creator and did not require the complete rejection of logic.

Another philosophical advance of the Upanishadic period was that religion was transformed from the realm of bookish parroting of scriptures to the realm of advanced intellectual debate and polemics. The Upanishadic philosophers did not lay down their conclusions as rigid doctrines or inviolable laws but as seductive parables – sometimes displaying remarkable worldly insight and analytical skill. By attempting to win over their followers through analogies from nature, and by employing the methods of abstract reasoning and debate, they created an environment where dialectical thinking and intellectual exchanges could later flourish.

In the very process of their questioning, (and albeit speculative reasoning about god), they had opened the door for rationalists and even outright atheists who took their tentative questioning about the role and the character of god as “creator” to conclusions that rejected theism entirely. But in either case, many rationalist and/or naturalist philosophical streams emerged from this initial foundation. Some were nominally theistic (but in the abstract Upanishadic vein), others were agnostic (as the early Jains), while the early Buddhists and the Lokayatas were atheists. Thus even though the Upanishads contained much that should rightly be dismissed as abstruse intellectual jugglery and philosophical mumbo-jumbo, the Upanishadic philosophers had levelled the ground for the seeds of rationalism to flourish in Indian soil.

The Vaisheshika School

The Vaisheshika school was an early realistic school whose main achievement lay in it’s attempt at classifying nature into like and unlike groups. It also posited that all matter was made up of tiny and indestructible particles – i.e. atoms that aggregated in different ways to form new compounds that formed the variety of matter that existed on the earth.

Their philosophy was described through the enumeration of the following concepts: Dravya (Substance), Guna (Quality), Karma (Action), Samanya (Generality), Visesa (Particularity), Samavaya (Inherence) and abhava (non-existence).

Dravya (or substance) was understood as the specific result of a particular aggregate effect – i.e. the combination of atoms in a unique way. Substances were repositories for qualities and actions. Guna or quality was that which resided in a dravya. Qualities did not however contain qualities themselves. 24 qualities were enumerated, such as – color, form, smell, touch, sound, number, magnitude, distinctions, conjunction, disjunction, nearness, remoteness, heaviness, fluidity and viscosity. (As was typical of the times, psychological attributes such as pleasure, pain, desire, aversion, effort, tendency, cognition, impression, and ethical attributes such as merit and demerit were also included in the list, i.e. – qualities that were inapplicable to inanimate objects were not treated separately)

Action or Karma represented physical movement. Unlike quality which was passive, Karma was dynamic. Action was the determinant of conjuction and disjunction. Five types of action were noted: throwing upwards or downwards, contraction, expansion and locomotion.

Satta or physical existence was viewed as being the common attribute of substance, quality and action – i.e. only existing (as opposed to imaginary) entities could have substance, qualities and be capable of action.

Samanyata or ‘generality’ was seen as a mental construct to create common classes of substances, qualities or actions while Visesata (particularity) was used to identify and separate individual items from their general classes. Samavaya or inherence was a relation that existed in those things that could not be separated without destroying them.

Four categories of Abhava as negation or non-existance were listed: pragabhava or prior non-existance, referring to the absence of an object before it’s creation; dhvamsabhava or posterior negation, as the absence of an object after it had been destroyed; anyonyabhava or mutual non-existance, refering to an object being distinct and different from the other; atyantabhava or absolute non-existence, indicating non-existence in the past, present and future, citing the example of air as permanently lacking in smell – (which was presumably true in a period where air pollution must have been uncommon!).

An important contribution of the Vaisheshika school was a careful study of the time-relation in a chain of causes and effects. In a very rudimentary way, the school (along with other such schools) anticipated the theory of time calculus which could also be extended to space calculus.

The Vaisheshika school thus served as an important step in the study of science by enumerating concepts that could further the study of physics and chemistry. In addition, the the study of medical science (including veterinary science) received considerable impetus from such attempts at methodical observation and classification.

The Nyaya and related schools

The Nyaya schools complemented and built on the Vaisheshika school by elaborating on the process of accumulating valid scientific knowledge through accurate perception and generating valid inferences.

The school articulated four means of acquiring valid knowledge: pratyaksha or perception through one of the senses; anumana or inference; upamana or comparison with a well-known object; or shabda – verbal testimony.

The conditions of perception, and it’s range and limits were carefully studied. Trasarenu – the minima sensibile (i.e. the minimum visible), anubhuta-rupa – the infra-sensible, abhibhuta – the obscured perception , and anubhuta-vriti – potential perception, were recognized as different types of perception.

A general methodology of ascertaining the truth (tattva) was described which consisted of describing a proposition (uddesa), the ascertainment of essential facts obtained through perception, inference or induction (laksan or uppa-laksana), and finally examination and verification (pariksa and nirnaya). This process could involve examples (drishtanta), logical arguments (avayava), reasoning (tarka) and discussion (vada) – , intellectual exchange, or interplay of two opposing sides in the process of arriving at a decisive conclusion. A successful application of this method could result in a siddhanta – i.e. established principle – (or in the case of mathematics – a theorem or theory) elucidated through proofs (pramana). Alternatively, it could lead to a rejection of the initial proposition.

The Nyaya school identified various types of arguments that hindered or obstructed the path of genuine scientific pursuit, suggesting perhaps, that there may have been considerable practical resistance to their unstinting devotion to truth-seeking and scientific accuracy. They list the term jalpa – an argument not for the sake of arriving at the truth but for the sake of seeking victory (this term was coined perhaps to distinguish exaggerated and rhetorical arguments, or hyperbole from genuine arguments); vitanda (or cavil) to identify arguments that were specious or frivolous, or intended to divert attention from the substance of the debate, that were put-downs intended to lower the dignity or credibility of the opponent; and chal – equivocation or ruse to confuse the argument. Three types of chal are listed: vakchala – or verbal equivocation where the words of the opponent are deliberately misused to mean or suggest something different than what was intended; samanyachala or false generalization, where the opponents arguments are deliberately and incorrectly generalized in a way to suggest that the original arguments were ridiculous or absurd; uparachala – misinterpreting a word which is used figuratively by taking it literally. Also mentioned is jati, a type of fallacious argument where an inapplicable similiarity is cited to reject an argument, or conversely an irrelevant dissimiliarity is cited to reject an argument.

The Nyaya school also recognized that intelligent and meaningful debates were not possible if certain fundamental principles and basic definitions and concepts were not mutually accepted. Nigrahasthana was the term used to identify disagreements based on absence of mutually acceptable first principles. An example might be a debate between a theist who rejected logic, and a non-theist who rejected faith.

The Nyaya school also listed five classes of logical fallacies (hetvabhasa) : savyabhichara or the inconclusive type which employed reasoning from which more than one conclusion could be drawn but was used to insist on a single specific conclusion; viruddha or contradictory, where the reasoning used actually contradicted the proposition to be established; kalatita – where the elapse of time had made the argument invalid; sadhyasama, the unproven type, where the reasoning employed rested on arguments or principles that had not been proven and require proofs themselves – i.e. this was the type of fallacy where one unproven result was merely converted into another unproven result.; and finally prakaranasama – where the reasoning employed provoked the very question it was designed to answer – i.e. a recursive fallacy.

In this manner, the Nyaya school defined a very sophisticated school of rational philosophy where the process of scientific epistemology was analyzed threadbare and all the dangers of unscientific reasoning and propaganda ploys were skillfully exposed.

Causality

Buddhist and Jain scholars, as well as later Hindu scholars offered their own approaches to scientific reasoning. Virtually all the rational schools were concerned with describing causality and causal relationships, and recognized that effects may not have single causes but may require a group or conjunction of causes to occur. Buddhist scholars emphasized that cause and effect need not have a linear effect but that desired effects may also require the right conditions for their fruition. (That is to say that for a plant to grow successfully, it would not only need the right seed, but that it would also need the right type of soil, fertilization, sunlight and water.)

Both the Jains and the Buddhists correctly speculated that a potential for the desired effect must also be present in the cause or causal agent. (For instance, only a mango seed could produce a mango tree because only the mango seed incorporated the potential of developing into a mango tree.) As another example, one could note that something with brittle properties such as glass might break upon impact whereas something strong such as steel would survive. Thus a physical impact on substances of different properties would have different results.

The Nyaya school also recognized co-effects – i.e a series of antecedants could cause a series of effects – either successive and staggered in time, or near simultaneous. Nyaya texts on causality indicate that there was an awareness that light travelled at a very high speed but the transmission of light was not instantaneous.

Buddhist and Jain Atomic Theories

The Buddhist and Jain philosophers also proposed their own variations of the atomic theory. Like the Vaisheshikas, atoms were perceived as infinitely small by the Jainas. But the Jainas went a step further by positing that the union of atoms required opposite qualities in the combining atoms – as is true in the case of electrovalent bonding. However, they erred in thinking that covalent bonding (which does not require opposite polarities in the combining atoms) could not occur. But their intuition that opposite polarities created mutual attraction and facilitated chemical reactions was correct. In the Buddhist view, matter was in fact an aggregate of rapidly recurring forces or energy waves. Their theory was illustrated with examples drawn from natural phenomenon involved with light emission. An atom was perceived as a momentary flash of light combining and separating from other atoms according to strict and definite laws of causality. Physical matter was thus seen as a denser and more concentrated form of light. Although at odds with other atomic theories of the time, their approach fit in with their general view that all things in nature were temporal, that there was constant change in nature – that degradation and renewal were continuous processes.

The Syadvada system of Jain Logic

Jain philosophers also made certain important contributions to the science of epistemology by proposing that the truth of a concept or observation could not only be true or false but indeterminate – and combinations of the above – such as true under some conditions (or true at a particular time or place – or true based on the validity of certain inferences) and false under other conditions, or true under some conditions but indeterminate under others, and so on. This led to a matrix of seven possible states of the truth

Jaina rationalists also studied the relationship between the universal and the particular and made important points concerning generalities and individual peculiarities. They also noted that objects in the real world exist in a network of relationships with each other – and have specific attributes that mark them temporally and spatially: “Every real is thus hedged round by a network of relations and attributes, which we propose to call its system or context or universe of discourse, which demarcates it from others.” Jaina philosophers also successfully synthesized earlier debates on change and permanence by positing that all objects (or parts of objects) passed through phases of “existence, persistence, and cessation” and that reality was therefore a complex combination of things relatively permanent yet also relatively changing.

These ideas thus formed the foundations of Indian science and contributed to the gradual elaboration of mathematics and astronomy, as well as agricultural and meteorological sciences. Developments in metallurgy and civil engineering also followed. Medicine and surgery perhaps received the greatest and the earliest impetus from these developments. Developments in philosophy also led to concomitant developments in the realm of art and culture.

Yet. to a considerable extent, knowledge about the progress of science and reason in Indian history is often scarce. These (and other such) historical contributions were either denied or demeaned during the process of colonization, and are only now beginning to be re-acknowledged within India and abroad. But in A. D 1068, Indian contributions to the mainstream of science were held in great esteem and readily acknowledged in some parts of the world:

Here is what Said Al-Andalusi, an 11th C Spanish scholar, court historian and chronicler wrote then: “Among the nations, during the course of centuries and throughout the passage of time, India was known as the mine of wisdom and the fountainhead of justice and good government and the Indians were credited with excellent intellects, exalted ideas, universal maxims, rare inventions and wonderful talents … They have studied arithmetic and geometry. They have also acquired copious and abundant knowledge of the movements of the stars, the secrets of the celestial sphere and all other kinds of mathematical sciences. Moreover, of all the peoples they are the most learned in the science of medicine and thoroughly informed about the properties of drugs, the nature of composite elements and peculiarities of the existing things.”